Piano-player action



- E. H. nouns. PIANO PLAYER ACTlON.

APPLICATION FILED SEPT. 3,1920.

Patented May 2, 1922.

ATTORNEYS.

IIIIIFIIII PATENT OFFICE.

EDGAR HENRY DODDS, OF STROUD GREEN, ENGLAND.

Specification of LettersP-atent.

PIANO-PLAYER ACTION.

Patented May 2,1922.

Application med September 3, .1920. Serial No. 408,011.

To all whom it may concern.

Be it known that L'Eooan HENRY DoDDs, subject ofthe Kingof Great Britain and Ireland, residing at 25 Albert Road, Stroud Green, in the county of Middlesex, England, have invented certain new and useful 1mprovements in Piano-Player Actions, of which the followingis a specification.

My invention relates to improvements in the construction of pneumatic actions for automatic musical instruments, piano players and the like, as described in my co-pending patent application No. 333,056, filed October 27th,1919.

The present invention comprises the detailed improvements in the construction of pneumatic actions as described hereafter in comunction with the accompanying sheet of illustrative drawings in which Fig. 1 is a' vertical section through a pneumatic action constructed according to the present invention and showing the upper or atmospheric valve open. 1 I

- Fig.2 is a similar view to- Fig. 1 but with the upper or atmospheric valve closed.

Fig. 3 is a plan of the improved pneumatic action.

chamber and L shaped valve member, and I Fig. 5 is a perspective view of a pneumatic showing the valve chamber with thecover plate and valve memberremoved.

Referring to the'drawings the pneumatic 1 of each unit of the pneumatic action is provided with a valve chamber 2 at its inner end, which valve chamber 2is open upon its,

upper and rear faces, and these open faces are covered. by an L shaped'metal plate 3. Packing strips 4 of soft leather or other suit able material are provided under the edges of this 'L shaped metal plate so as to ensure an air-tight fit between it and the sides of the valve chamber 2. The upper corners of the sides f the valve chamber 2 are cut away so as to leave spaces 6 for the reception of bearing pins 7 which project on-each side of the bent metal valve plate 8. A strip of felt or other suitable material 9'is provided in the space 6 for the bearing pin7 to rest upon, and the corne'rs of the packing strips-4'where they pass overthis space 6 are slit to enable the bearing pin 7 to be inserted into or removed from these spaces. j 1 1 The bent metal valve plate has upper and lower valve members 10 and Y11 which respecof the L shaped metal tively operate to-control ports 12 and 13 in the' L shaped cover plate The upper port 12 communicates directlyto the atmosphere, and a loose valve 14 is secured to the underside of the cover plate 3 in a position to control the port 12 and adapted to be actuated by the upper valve member 10 of the valve plate 8. This valve 14 comprises a metal plate 15 having a facing of soft leather or othersuitable material 16, a portion 17 of which over-- laps one edge and is secured to the underfaee plate 3 so as to act as a hinge for the valve 14.

On the back of the metal plate 15 is provided a small disc of felt or other suitable material to form an abutmentwhich rests upon the upper valve member 1 of the hinged valve plate 8.

The lower or vertical valve member 11 is provided with a facing of soft leather or other suitable material 18 and normally bears against the inner vertical face of the Lshaped plate 3 so as to close the port 13 communicat ing with the diaphragm chamber-19 through the passage 20. This diaphragm chamber 19 is formedin one face of thefwooden or other p block or bar 21 to the'front of which each of Fig. 4 is an enlarged detail of the valve the units comprising a pneumatic 1 and valve small chamber 26 communicating with a pas.

sage 27 through the aperture 28. This a passage 27 isconnected by a flexible tube or other connection from its other endtoone of the apertures in thetracker'bar so as to admit atmospheric pressure to the rear side of the diaphragm 25 when theaperture in the track er bar is uncovered bythe music. Suitable packing 29 is provided between the block or b'ar21 and its cover 24 so as to ensure an air tight joint.= 1

The diaphragm' 2 5 c'onsistsof a disc of flexible material secured at its edges over 7 the small chamber 26 and at its centre is secured a disc 30 of felt or other suitable material in which 1s mounted a valve actuiii) (mil

at-ing pin 31. This valve actuating pin is supported in a cross bar 32 secured to the front "face of the diaphragm chamber 19 and extending across the aperture 20. This bar 32 may be of fibre or other suitable material, and acts as a guide to support the valve pin 31, the tree end of which is adapted. to press against the valve member 11 ot the L shaped valve plate 8 so as to force it trom its seating to uncover the port 13 ind to cause the valve member to press :he valve 14: against the upper member of ;he L shaped plate 3 so as. to close the aperrure 12 when atmospheric pressure is admitted to the chamber so as to distend :he diaphragm 19. This results in the p11eu mat-ic it being cut cit from the atmosphere and placed into communication with the wind chest through the diaphragm chamber 19 so that the pneumatic will be contracted to actuate the piano action.

in. order to cause the diaphragm to again return to its normal or deflated pos tion after the pneumatic has been actuated, small vent or by-pass is provided between the tiliaiphrag m chzunber l9 and the passage 27 leading to the tracker bar and communicating through the aperture 28 to the chamber 26 upon the other side of the diaphragm. This allows the pressure or suction upon both sides ot the diaphragm to be equalized when not in action.

To obtain satistactm-y action of: the pneumatic it is necessary that this by-pass or vent be reguli'ted with considerable nicetv. In order to do this in a simple and effective manner I employ a small tube 33 inserted into the cover 24. so that one end communirates with the diaphragm chamber 19. and a small aperture 34- is provided in its side so as to communicate with the passage 27. In the outer end of this tube is provided a valve pin 35 screw-threaded so as to engage in the outer end of the tube and adapted to be screwed in and out of this tube so that its conical end 36 will operate to control the etl'ective size of the aperture 34- and thus vary the speed with which the pressure or suction upon both sides of the diaphragm will. become equalized.

This regulating device is extremely useful in tuning up the action, and since the screwed valve pin 35 may be readily regulated so as to give exactly the etl'ect desired without having to dismantle any of: the apparatus, correct tuning of instrument may be quickly and accurately attained.

I cl aim '1. In a pneumatic piano player action, a pneumatic. a valve chamber at one end of the pneumatic, an L shaped plate to close the upper and rear faces of this chamber, packing strips around the edges, of the valve chamber over which the L shaped plate is secured, recesses in the sides or the valve chamber, a hinged valve plate, a. pin located in the angle of the valve plate and projecting into the recesses in the sides oil v the valve chamber, in which it is secured by the L shaped cover plate.

2. In a pneumatic piano player action, a pneumatic, a valve chamber at one end oi. the pneumatic, an L-shaped plate to close the upper and rear faces ct this chamber, packing strips around the edges of the valve chamber over which the L shaped plate is secured, recesses in the sides of the valve chamber, a hinged valve plate, a pin located in the angle of the valve plate and projecting into the recesses in the sides of thevalve chamber, in which it is secured by the L shaped cover plate, a separate valve hinged on the under face of the L shaped cover plate, a facing of soft material to this valve, a projecting edge to the soft material, secured to the cover plate and forming a hinge tor the valve, a disc of :lelt on. the back ot the valve adapted to butt upon the face of L shaped valve plate. the upper member of the cover plate having; an apen ture adapted to be closed by this valve when the L shaped valve plate is actuated.

3. In a. pneumatic piano player action, a pneumatic, a valve chamber at one end of the pneumatic, an L shaped. plate to close the upper and rear faces of this chamber, packing strips around the edges ot the valve chamber over which the L shaped plate secund, recesses in the sides of the valve chamber, a hinged valve plate, a pin located in the angle Ofl the valve plate and project ing into the recesses in the sides oi the valve chamber, in which it is secured by the L shaped cover plate. facing material on the lower member of the valve plate, an aperture in the lower member of the cover plate. normally closed by this facing on the lower member of the valve plate, a diaphragm, one side of which is in communication with the tracker bar and the other with the suction or wind chest, and a pin on this diaphragm adapted to actuate the valve plate.

l. In a pneumatic piano player action, a. pneumatic, a valve chamber at one end ot the pneumatic, an L shaped. plate to close the upper and rear faces of this chamber, packing strips around the edges of the valve chamber over which the L shaped plate is secured, recesses in the sides of the valve chamber,a hinged valve plate, apin locatedin the angle of the valve plate, and projecting into the recesses in the sides of the valve (5113111- ber, in which it is secured by the L shaped cover plate, a separate valve hinged on the under face of the L shaped cover plate, a facing of soft material to this valve, a projecting edge to the sott material secured to the cover plate and forming a. hinge tor the valve, a disc of felt on the back of the valve 7 adapted to butt upon the time of L shaped valve plate, and an aperture in the upper member of the cover plate adapted to be closed by this valve when the L shaped valve plate is actuated, facing material on the lower member of the valve plate, an aperture in the lower member of the cover late normally closed by this facing on the ower member of the valve plate, a diaphragm one side of which is in communication with the tracker, bar and the other with the suction or wind chest, and a pin on this diaphragm adapted to actuate the valve plate. 7

5. In a pneumatic piano player action, a pneumatic, a valve chamber at one end of the pneumatic, an L shaped plate to close the upper and rear faces of this chamber, packing strips around the edges of the valve chamber over which the L shaped plate is secured, recesses in the sides of the valve chamber, a hinged valve plate, a pin located in the angle of the valve plate, and projecting into the recesses in the sides of the valve chamber, in which it is Secured by the Li shaped cover plate, facing material on the lower member of the valve plate, an aper ture in the lower member of the cover plate normally closed by this facing on the lower member of the valve plate, a diaphragm one side of which is in communication with the tracker bar and the other with the suction or wind chest, and a pin on this diaphragm adapted to actuate the valve plate, a vent passage connecting the two sides of the diaphragm, a screw-threaded valve pin in the vent passage and adapted to be screwed in orvout to control thepassage of air through the vent to regulate the action of the pneumatic. I r

(S. In a pneumatic piano player action, a pneumatic, avalve chamber at one end of the pneumatic, an L shaped plate to close the upper and rear faces of this chamber, packing strips around the edges of the valve chamber over which the L shaped plate is secured, recesses in the sides of the valve chamber, a hinged valve plate, a pin located in the angle of the valve plate and projecting into the recesses in the sides of the valve chamber, in which it is secured by the L shaped cover plate, a separate valve hinged on the underface of the U shaped cover plate, a facing of soft material to this valve, a projecting edge to the soft material, secured to the cover plate and forming a hinge for the valve, a disc of felt on the back of the valve adapted to butt upon the face of L shaped valve plate, and an aperture in the upper member of the cover plate adapted to be closed by this valve when the L shaped valve plate is actuated, facing material on the lower member of the valve plate, an aperture in the lower member of the cover plate normally closed by this facing on the lower member of the valve plate, a diaphragm one side of which is, in communication with the tracker bar and the other with the suction or wind chest, and a pin on this diaphragm adapted to actuate the valve plate, a vent passage connecting the two sides of the diaphragm, a screw-threaded valvepin in the vent passage and adapted to be screwed in or out to con trol the passage of air through the vent to regulate the action of the pneumatic.

EDGAR HENRY DonDs. 

